施氮量对香料烟光合、蒸腾和水分利用效率的影响

Effects of Nitrogen Rates on Photosynthesis, Transpiration, and Water Use Efficiency of Oriental Tobacco Leaves

摘要: 为确定保山干旱环境下香料烟光合生理的适宜施氮量，试验研究了不同施氮量（75、60、45 kg/hm²）对香料烟叶片光合蒸腾和水分利用效率特征的影响。结果表明，随施氮量增加，叶片气孔导度，胞间CO₂浓度、蒸腾量降低，水分利用效率增加；单位叶面积所积累的干物质量以高施氮量最高，中等施氮量最低。试验表明，75 kg/hm²的施氮量有助于降低香料烟蒸腾作用，提高水分利用效率，并获得较高的干物质量。

Abstract: Effects of nitrogen rates on photosynthesis, transpiration and water use efficiency of oriental tobacco leaves in arid environment in Baoshan was studied in order to determine the optimum rate of nitrogen in arid environment. The results showed that stomatal conductance, intercellular CO₂concentration, transpiration rate decreased, and efficiency of water use increased with higher inorganic nitrogen fertilizer rates. The amount of dry matter accumulation per unit leaf area was largest with the highest nitrogen rate, and lowest with moderate nitrogen rate. Nitrogen rate of 75 kg/ha was most useful for lowering transpiration rate, improving its water use efficiency and getting a higher quality of dry matter.